Copter: remove setting position control's altitude max

AC_Avoid now takes responsibility for enforcing the alt limit and accesses inertial nav's limit directly

ArduCopter/ArduCopter.cpp

@@ -504,9 +504,6 @@ void Copter::one_hz_loop()
 
     check_usb_mux();
 
-    // update position controller alt limits
-    update_poscon_alt_max();
-
     // enable/disable raw gyro/accel logging
     ins.set_raw_logging(should_log(MASK_LOG_IMU_RAW));
 

ArduCopter/Attitude.cpp

@@ -302,17 +302,6 @@ void Copter::set_accel_throttle_I_from_pilot_throttle()
     g.pid_accel_z.set_integrator((pilot_throttle-motors->get_throttle_hover()) * 1000.0f);
 }
 
-// updates position controller's maximum altitude using fence and EKF limits
-void Copter::update_poscon_alt_max()
-{
-    // get alt limit from EKF (limited during optical flow flight)
-    float ekf_limit_cm;
-    if (inertial_nav.get_hgt_ctrl_limit(ekf_limit_cm)) {
-        // pass limit to pos controller
-        pos_control->set_alt_max(ekf_limit_cm);
-    }
-}
-
 // rotate vector from vehicle's perspective to North-East frame
 void Copter::rotate_body_frame_to_NE(float &x, float &y)
 {

ArduCopter/Copter.h

@@ -668,7 +668,6 @@ private:
     void auto_takeoff_set_start_alt(void);
     void auto_takeoff_attitude_run(float target_yaw_rate);
     void set_accel_throttle_I_from_pilot_throttle();
-    void update_poscon_alt_max();
     void rotate_body_frame_to_NE(float &x, float &y);
     void gcs_send_heartbeat(void);
     void gcs_send_deferred(void);